Well, I cannot comment about PopOS because I simply don't know how it is, but Bazzite on desktop has been great. I didn't need to install anything related to gaming because it already comes with everything on it.

Pretty much anything I needed is on the discovery store and it's handled like the app store on Android, so no headache of messing it up with installations or worrying about updates. Although, Bazzite is an immutable OS so anything that you need to install that's not on the store can be a headache.

Also, my computer is an old laptop, so I got a performance boost as the system feels way smoother now than with Windows.

About games, I played some indie games on Steam and Lutris and it worked flawlessly. But do note that for more recent systems, it appears to be some headaches, especially with NVIDIA graphics cards. I only play new games on streaming services, so I don't have those problems. But I do have some problems with the streaming service using my 8BitDo controller, but it's not related to the system, it's related to the service's bad drivers. When I stream the game using Steam, it's smooth sailing.

I have used both Bazzite and PopOs for more then a year. They are both great distros. The reason I stuck with Bazzite is ease of updates since its immutable (I am lazy and updated PopOS only when I absolutely needed, and updating bunch of system packadges after a long time always causes something else to screw up). PopOS on the other hand gives you complete control over how to install things, and system configuration.

TLDR, if you are a power user, then decide based on if you want an immutable system or not. If you are not, you can just flip a coin and choose, Bazzite has better ease of use compored to PopOS on theory, but if you encounter issues PopOS will be easier to troubleshoot because it has more users / information online.